1. Field of the Invention
The disclosure relates to a projection system with extending depth of field and the image processing method thereof.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98
Image processing systems are widely used in various kinds of applications. In addition to ordinary image function, image processing systems used in specific applications are usually required to have the capability to extend depth of field. Most ordinary imaging systems are required to have sharp image and faster imaging, i.e. small F-number, to enhance light energy usage efficiency. However, imaging systems with small F-number exhibit short depth of field. With projection systems, for example, due to the restriction of the conjugation relation between object and image, the image projected by a projection system will become blurry when the projection screen moves away from the optimum projection distance, unless a focus adjustment procedure is performed to the imaging lens of the projection system.
In addition to projection systems, an exposure system can increase its structural depth to width ratio after the exposure process if the exposure system has the feature of extending depth of field.
U.S. Pat. No. 6,069,738 discloses a projection system, which uses an image coder to generate a coded image of a desired projection image by an extended depth of field (EDF) mask and a known required image. After generating the coded image, the projection system provides the coded image to a light encoder to generate an encoded light. A project image, of which the clearance will not change with the location of the projection screen, can be produced after the encoded light passes through the EDF mask.
The development of projection systems with extending depth of field is vital for industry. In addition, users expect a projection system in which the image clearance is not sensitive to the location of the projection screen, and the projection lens thereof does not require additional focus adjustment.
Accordingly, there is a need to reduce the calculation load, to establish a forwarding protocol among cameras, and to implement a front-end embedded system, so as to meet industrial requirements.